A compact image pickup apparatus presently has come to be mounted on a mobile terminal such as a cell phone and PDA (Personal Digital Assistant). An image pickup apparatus is in the actual circumstances that mass-productivity of an image pickup apparatus to be mounted on a mobile terminal is demanded according to a recent spread of a large amount of mobile terminals and that further downsizing and cost reduction of an image pickup apparatus are demanded according to a demand of further reduction in size and thickness of a mobile terminal from users.
As a method to mount a large number of image pickup apparatuses at low cost, the following technique has been suggested recently. Optical elements are arranged together with electronic components such as IC chip on a substrate on which solder is potted in advance. By adding reflow processing (heating processing) to the substrate to melt the solder as the optical elements and electronic components are arranged thereon, the optical elements and electronic components are simultaneously mounted on the substrate.
On the other hand, for reducing the cost of an image pickup apparatus, many types of inexpensive thermoplastic resin has been used as a material forming an image pickup lens. In order to mount the image pickup apparatus with the above reflow processing, optical elements need to be heated with electronic components at about 200 to 260 degrees. However, lenses made of thermoplastic resin can be deformed by heat or changed in color under such the high temperature, which results in deterioration of its optical performance. As a solution of the problem, there has been known an image pickup lens employing a glass mold lens which is excellent in heat resistance (for example, refer to Patent Literature 1).    Patent literature 1: JP-A No. 2007-322839